About

POLARBEAR Rules Out Cosmic Birefringence

No rotation of polarization vector in cosmological distances

The polarization vector of cosmic background radiation could rotate during the course of its journey towards us, and if it did, it could also cause trouble for the Standard Model for electromagnetic interactions. To understand if this rotation is taking place, we need an “eye” that can see great distances, like POLARBEAR, an instrument located in Chile at the top of the Andes. The POLARBEAR research team (which includes SISSA) carried out measurements and recently published results, which can be found on the first page of the latest edition of Physical Review D.